Re: [Qemu-devel] [net, v1, 1/4] net: cadence_gem: Fix Tx descriptor update

[Michael Tokarev]

24.05.2014 10:38, Michael Tokarev wrote:
> [...]
>          if (tx_desc_get_last(desc)) {
> +            unsigned    desc_first[2];
> +
>              /* Modify the 1st descriptor of this packet to be owned by
>               * the processor.
>               */
>              cpu_physical_memory_read(s->tx_desc_addr,
> -                                     (uint8_t *)&desc[0], sizeof(desc));
> -            tx_desc_set_used(desc);
> +                                     (uint8_t *)&desc_first[0], 
> sizeof(desc));
> +            tx_desc_set_used(desc_first);
>              cpu_physical_memory_write(s->tx_desc_addr,
> -                                      (uint8_t *)&desc[0], sizeof(desc));
> +                                      (uint8_t *)&desc_first[0], 
> sizeof(desc));
>              /* Advance the hardare current descriptor past this packet */
> 
> This is quite fun.
> 
> Can we, please,
> 
>  a) s/unsigned/uint8_t/ in the variable declaration,
>    and remove the useless casts and "readdressing" everywhere?

Um, no, this is ofcourse wrong - tx_desc_set_used() expects unsigned.
Still it's possible to remove "readdressing", instead of

  (uint8_t *)&desc[0]

use

  (uint8_t *)desc

The second point stands.. ;)

> and, more interesting,
> 
>  b) s/sizeof(desc)/sizeof(desc_first)/g
>     ? :)
> 
> Thanks,
> 
> /mjt
>